Margins in Laryngeal Squamous Cell Carcinoma Treated with Transoral Laser Microsurgery: A National Database Study.

Objectives: To determine national positive margin rates in transoral laser microsurgery, to compare patients with positive and negative margins, and to identify factors associated with positive margins.
Study Design: Retrospective review of the National Cancer Database.
Setting: Population based.
Subjects/methods: Patients included those with TIS-T3 laryngeal squamous cell carcinoma (2004-2014). Univariable and multivariable logistic regression were used to identify predictors.
Results: A total of 1959 patients met inclusion criteria. The national positive margin rate was 22.3%. Sixty-five percent of patients had T1 disease; 94.3% were N-negative; and 74.0% had glottic tumors. Fifty-eight percent of patients were treated at academic centers, and 60.6% were treated at facilities performing <2 cases per year. On multivariable analysis, factors associated with margin status included facility volume (odds ratio [95% CI]; in cases per year: 0.93 [0.89-0.97], P = .001), academic status (vs nonacademic; academic: 0.70 [0.54-0.90], P = .008), T-stage (vs T1; T2: 2.74 [2.05-3.65], T3: 5.53 [3.55-8.63], TIS: 0.59 [0.38-0.92], P < .001), and N-stage (vs N0; N1: 3.42 [1.79-6.54], N2: 2.01 [1.09-3.69], P < .001). Tumor subsite was not associated with margin status.
Conclusion: The national positive margin rate for laryngeal laser surgery is 22%, which is concerning given the equivalent survival benefit offered by surgery and primary radiation and the increased likelihood of bimodal therapy in the situation of positive margins. Cases treated at nonacademic centers and those with lower caseloads had a higher likelihood of positive margins. There was a linear association between T-stage and likelihood of positive margins, with T3 tumors being 5 times as likely as T1 to yield positive margins. This study highlights the importance of proper patient selection for transoral laser microsurgery resections.